Machine for the manufacture of screws



Oct. 8, 1929. J. F. ARNOLD 1,731,036

CHINE FOR THE MANUFACTURE OF SCREWS Filed Jar 1. 2;, 1926* aSheets-Sheet 1 y, saiZ f Oct. 8, 1929. J. F. ARNOLD CHIN? FOR THEMANUFACTURE OF SCREWS Filed Jan. 23. 1926 sheets-sheet 2 w H V IQ i. T W0 %Q 7 mAH U q h nl lu: H um aw a 0 #U Q ra Am m0 #fl .VN $.15 WJI m E sm u U 7AM Gm o 1 .A OD qq m. n

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Oct. 8, 1929. A L 1,731,036

I CHINE FOR THE MANJFACTURE 0F SCREWS Filed Jan. 23. 1926 3 Sheets-Sheet3 Patented Oct.- 8, 1929 UNITED STATES PATENT OFFICE JEAN snanqors.umom), or JUVISY, rmcn MAC HINE FOR THE MANUFACTURE OF SCREWSApplication filed Ianuary23, 1926, Serial m. 83,188, and in Germany July24, 1925.

My invention relates to improvements in the machines forming the threadsof quickmotion screwsby the use of a milling cutter.

In particular, one of the said improvements consists in the use of aplurality of juxta posed and superposed stocks, each of which contains achuck for holding the screw blank, in such manner that the blanks willbe disposed in a circle about the milling cutter.

v1o By this arrangement I-obtain in a single Fig. 1 shows the successiveforms of a screw blank.

Fig. 2 shows the manner in which'the screw- 2 holdlng stocks are brou httogether and the millin cutterv brought forward, the tapered part 0%said cutter serving to form the point of the screw.

Fig. 3 shows the said stocks in the separated position, with the millingcutter brought further forward and so as. to engage the blank.

Fig.4 is a like view with the milling cutter at the end of its strokeand the work completed.

Fi 5 shows the separation of the stocks for t e disenga ement and theback motion of the cutter, an the jaws of the screw chucks now open forthe expulsion of the finished screws.

Fig. 6 is a side view of a machine, partly in section.--; Fig. 7 is acorresponding plan view.

Figs. 8 and 9 are cross sections respectively along lines 8-8 and 99 inFig. 6.

The following descri tion relates, by way of example, to a machinecomprising two stockfor holding the screw blanks, for the sake ofclearness in the drawings.

. The driving pulley B (Figs. '6 and 7 imparts the motion to theblank-holding stocks C and C, to the feeding elements D and'E, and tothe various cams serving for clamping, coupling or feedingpurposes. Thepulley B which is keyed to the shaft of the worm B (Fig. 6) drives,through the medium of the gear wheels B and 13 the power shaft Bcomprising the Cardan device B The shaft 18 which is situated below thebed A of the machine carries the gear wheel 13 which drives the twostocks C and C b means of the gear wheels C and C whic are loose on theshaft of the said stock's (see also Fig. 9).

To provide for the variable spacing of the 65. said stock C, C duringworking, and also to assure a constant gear engagement, irrespective ofthe relative positions of wheels C C, and B the wheels C C and B areprovided with lateral rolling cheeks C and are urged into contact by thesprings C disposed in a casing G 'mounted-on the shaft C and the wheelB", said cheeks preventing the teeth of the wheels from engaging toodeeply.

The main pulley B also drives the cam shafts B B 134, 13 by means of theworm B the worm wheel B and the bevel gear ing B (Fig. 7).

The cutting wheel F is separately driven by the pulley F keyed tothecutter shaft which is rotatable in the stock F said stock is movablein a guide slot, lengthwise of the piece of work and also lengthwiseofthe machine, by means of the cam F which is keyed to the shaft B andthrough the medium'of the adjustment roller F -As shown in Fig. 2, thetaperedpart of the milling cutter serves in the first place to cut thepoint of the screw and the part a then forms the screwthread.

The screw blanks are carried by the respective stocks 0 and C. Thesliding sleeves C (Fig. 7) are simultaneously controlled (in the twostocks), by the respective forks C which are mounte upon the commonshaft C which is controlled by the cam C keyed to the shaft B, throughthe medium of the roller lever (l mounted on the shaft (1 (see also Fig.6). v

The sleeves C control by means of their tapered surface the opening andclosing of the pivoted jaws or clamps C7 holding the screw blanks 2.During the back motion of the.

said sleeves, the awswill open under the action of springs C The chuckshafts C are simultaneously driven by the friction wheels C and 0' bymeans of the friction clutch sleeves C which n i are actuated by theforks C, the shaft C, the roller lever C and the single cam C .which iskeyed to the shaft B The lever C" is keyed to the shaft C (Fig. 9). In

this manner the gear wheels C and C can which are mounted in regulatingforks. The

proper spacing of the stocks G and C is assured by springs urging therollers G into contact with the cams B B. The spacing is further ensuredby'the thrust of the gear wheel B upon the wheels C and (3' the wheel Bbeing urged outwardly by the springs C acting upon its shaft. It shouldbe noted that the movement for the spacing of the'stocks might also beobtained by the use-of tapered wedges under cam control.

. the said blanks to drop into position rod D which is given areciprocating motion The I blanks, whose head is preliminarily formed (d'Fig. 1) are placed in the hopper D comprising two vertical guides D andD 1 Fig. 7) which are both actuated b the cam I) (Fig. 6) through themedium 0 the lever Di. The said guides receive the blanks from thebottom of the hopper and lead them to the sliding blank-carrier E (Fig.7). A device comprising feeding studs or arms D allows one by one uponthe said blank-carrier.

The said studs or arms are mounted on a by the lever E controlled by thecam E The blank-carrier E is mounted upon a support or base E (Fig. 8)and provided with 'two pivoted and spring-mounted feeding holders E E(Fig. 7) whichmay be of any well known type feeding the respectivestocks C C; said carrier E is driven by the cam E through the medium ofthe lever E which is controlled bya reaction spring.

Fig. 8 shows the studs I) mounted on the rod '1) permitting successivela blank to pass while arresting the n'extbl The spacing between the twostuds 1) corresponds to the diameter of a blank. Therefore, a blank canpass down the chute D and become engaged between the two studs D As rodD is moved back, the blank is released by the withdrawal of the lowerstud I), while the upper stud D advances to hold back the next blank sothat each time onlyone blank will descend. The blanks are dropped uponthe said feeding holders E (Fig. 8) which are pivoted on carrier E andbring them opposite the jaws C of the chucks.- The said pivotedfeeding-holders allow a certain play for the blanks when placed in thejaws and when the carrier E recedes.

The holder E being pivoted on carrier E permits the latter to return tothe rear while leaving behind a blank clamped between the jaws C Sincethis blank was located in a groove of E the latter must slightly descendto leave the blank clamped between the jaws. When leaving chute D, theblanks drop by one in the groove of E (Fig. 8). The

carrier E is periodically displaced by the,

lever E? controlled by cam E (Fig. 7). Thus the holder E comes oppositethe jaws of stock C, while the holder E comes opposite the jaws of stockC.

When the said blanks are about to' be inserted in? the chucks, and whenthey are brought by the carrier E opposite the center of the said jaws,the blanks ((1 are driven between the jaws C (Fig. 7) by the pivotedpush-pieces G which means of their projections Gr (Fig. 7). The saidpush-pieces G are mounted on a shaft impel the blanks by,

(Fig. 7) which is provided with a roller lever which is controlled bythe cam Gr (see also Fig. 8).

At the exact moment at which the said 'aws clamp the blanks, the feedinand impe 'ng devices will disappear in or er to allow the milling cutterto act.

The gear wheelsB and B are accessible from the exterior and areinterchangeable so as to vary the forward feed of the milling cutter aswell as the rate of rotation'of the blank-holding chucks The precedingdescrlption shows the various operatlons upon the blanks (d Fig. 1)

inwhich the point of the screw is formed by -means of the taperedpartZhof the milling cutter (Fig.2) and the thread is then formed by thedisk part of the milling cutter a, the:

latter being moved as shown in Figs. 2, 3, 4 and 5 while the stocks G, Care moved. towards or from each other by the correspondmg amount.

It should be noted that all the operative arts of the machine aremounted on the same ed and are thus readily accessible, so that all theparts can be mounted and adjusted with great facility.

Obviously, the several parts may be replaced by equivalent parts servinga like purpose.

I claim:

IL A screw milling machine, comprising a rotary milling cutter having aplurality of prising gears rotatable on the chuck shafts and adapted tobe clutched thereto, a gear mounted on a movable shaft and engaging saidchuck gears, spring means maintaining said gear in engagement with saidchuck gears irrespective-of their relative positions,

and cam devices for controllingthe clutching 0f the chuck gears on thechuck shafts.

In testimony whereof he has alfixed his signature.

JEAN FRANQOIS ARNOLD.

